Ultraviolet Imaging Spectrometer

Wide-field imaging systems equipped with objective prisms or gratings have had a long history of utility in groundbased observations of meteors and comets. Deployment of similar instruments from low Earth orbit would allow the first UV observations of meteors. This instrument can be used for comets and Lyman alpha coronae of Earth-orbit-crossing asteroids. A CaF2 prism imaging spectrograph designed for stellar observations was used aboard Skylab to observe Comet Kohoutek (1973f), but its 1300-A cut-off precluded Lyman alpha images and it was not used for observation of meteors. Because the observation of the UV spectrum of a meteor has never been attempted, researchers are denied the opportunity to obtain composition information from spectra at those wavelengths. We propose construction of a flight instrument functioning in the 1100-3200 A spectral range that is suitable for a dedicated satellite ('Quick Star') or as a space-station-attached payload. It can also be an autonomous package in the space shuttle cargo bay

Heavy metal toxicity as a kill mechanism in impact caused mass extinctions

Heavy metals that are known to be toxic exist in carbonaceous chrondrites at abundances considerably in excess to that of the terrestrial crust. An impactor of relatively undifferentiated cosmic matter would inject into the terrestrial environment large quantities of toxic elements. The abundances of toxic metals found in the Allende CV carbonaceous chondrite and the ratio of meteoritic abundance to crustal abundance are: Cr, 3630 PPM, 30X; Co, 662 PPM, 23X; ni, 13300 PPm, 134X; se, 8.2 PPM, 164X; Os, 0.828 PPM, 166X. The resulting areal density for global dispersal of impactor derived heavy metals and their dilution with terrestrial ejecta are important factors in the determination of the significance of impactor heavy metal toxicity as a kill mechanism in impact caused mass extinctions. A 10 km-diameter asteroid having a density of 3 gram per cu cm would yield a global areal density of impact dispersed chondritic material of 3 kg per square meter. The present areal density of living matter on the terrestrial land surface is 1 kg per square meter. Dilution of impactor material with terrestrial ejecta is determined by energetics, with the mass of ejecta estimated to be in the range of 10 to 100 times that of the mass of the impactor. Because a pelagic impact would be the most likely case, the result would be a heavy metal rainout

Ultraviolet spectroscopy of meteoric debris of comets

It is proposed to carry out slitless spectroscopy at ultraviolet wavelengths from orbit of meteoric debris associated with comets. The Eta Aquarid and Orionid/Halley and the Perseid/1962 862 Swift-Tuttle showers would be principal targets. Low light level, ultraviolet video technique will be used during night side of the orbit in a wide field, earthward viewing mode. Data will be stored in compact video cassette recorders. The experiment may be configured as a GAS package or in the HITCHHIKER mode. The latter would allow flexible pointing capability beyond that offered by shuttle orientation of the GAS package, and doubling of the data record. The 1100 to 3200 A spectral region should show emissions of atomic, ionic, and molecular species of interest on cometary and solar system studies

Computer-assisted quantification of caix membrane immunoreaction destined for the clear cells in renal carcinoma. A pilot study.

Introduction/ Background Carbonic Anhydrase IX [CAIX] has been considered as a candidate prognostic factor in clear-cell renal carcinoma [CCRC], however the supporting evidence is conflicting. CAIX is strongly induced by hypoxia via HIV-1α, and in CCRC via mutations to the VHL gene. CAIX expression could be identify as an immunohistochemical predictor of CCRC patients outcome but the published studies related to the patients prognosis have based on the diverse quantification protocols of CAIX expression (TMAs vs. whole tissue section; semiquantitative vs. computerised image analysis; with/without intensity scoring; with various software). The available commercial image analysis tools are mainly for general purpose e.g. software for breast carcinoma HER2 membrane immunoreaction has been used in various tumour tissue studies. However the cytological images of CCRC and breast carcinoma show essential differences related to the nuclei (size, outlines, intracellular location) and nuclear/cytoplasmic proportion which could influence the measurement credibility in maladjusted algorithm. Aims The aim of our study was to evaluate an algorithm for quantification of the membranous CAIX expression specifically dedicated to CCRC (“snake variant”) in comparative analysis to applied HER2 breast cancer algorithm for CCRC. Methods In the quantitative analysis of the specimen, the image processing follows: recognition of the cell nuclei; segmentation of the immunoreactive cell membranes; the assignment of the membrane segments to an individual cell. The last step is challenging for analysis due to frequent discontinuities in membranous immunoreaction, great variability of cellular counters and intracellular nuclei location. Because the classical watershed method for the individual cell separation is insufficient, the snake active contour method was applied, starting from each nucleus outline. The built gradient image allowed to select the most adequate parameters in the snake adaptation process. The recognized snake represents the membrane associated with the particular cell. The material includes records of 39 patients with the histopathologically verified diagnosis of CCRC who had nephrectomy (between 2009-2011) and were treated with tyrosine kinases agents (the Clinic of Oncology registry). 74% (29 out 39) of patients presented stage I - T1 N0; 20,5% - stage III and 5,4% stage TII. The formalin-fixed tissue sections of the resected CCRCs (the Pathology Department registry) were immunostained for CAIX protein using CAIX antibody (clone NB100-417) (Antibodies-online GmbH) with EnVisionTM (DAKO) according to the manufacture recommendations. The representative digital images were selected from each Whole Slide Image (scanned with Aperio, under 20x) and were assessed automatically by 3 independent observers using two algorithms: “snake variant” and “breast HER2”. The extend of staining (percentage) was scored in the 10% intervals of CAIX positive carcinomatous cells and the intensity of immunoreaction was evaluated in 3 grade scale (1-3). ResultsThe obtained results have been under investigation for the intra- and inter-observer accuracy as well as for the comparative data analysis of both types of algorithm. The statistical analysis has been incorporated. This approach explores a new possibility of the computerised quantitative estimation of the membrane CAIX immunoreaction destine

Exposing metal and silicate charges to electrical discharges: Did chondrules form by nebular lightning?

In order to investigate the hypothesis that dust aggregates were transformed to meteoritic chondrules by nebular lightning, we exposed silicatic and metallic dust samples to electric discharges with energies of 120 to 500 J in air at pressures between 10 and 10^5 Pa. The target charges consisted of powders of micrometer-sized particles and had dimensions of mm. The dust samples generally fragmented leaving the major fraction thermally unprocessed. A minor part formed sintered aggregates of 50 to 500 micrometer. In a few experiments melt spherules having sizes smaller than 180 micrometer in diameter (and, generally, interior voids) were formed; the highest spherule fraction was obtained with metallic Ni. Our experiments indicate that chondrule formation by electric current or by particle bombardment inside a discharge channel is unlikely.Comment: Accepted by Icaru

Moessbauer Mineralogy of Rock, Soil, and Dust at Gusev Crater, Mars: Spirit's Journey through Weakly Altered Olivine Basalt on the Plains and Pervasively Altered Basalt in the Columbia Hills

The Moessbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe(3+)-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe(3+)/Fe(sub T)Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, Keel, and Paros with Fe(3+)/Fe(sub T) approx.0.6-0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe(2+) from Ol+Px is 40-49% and 9-24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm approx.3-6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt approx. 10-15%). Remaining Fe is present as npOx, hematite, and goethite in variable proportions. Clovis has the highest goethite content (Fe from Gt=40%). Goethite (alpha-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe(3+)/Fe(sub T) approx. 0.3) occur throughout Gusev crater (approx. 60-80% Fe from Ol+Px, approx. 10-30% from npOx, and approx. 10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe(3+)-sulfate (approx. 65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust

Inositols: From established knowledge to novel approaches

Myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) are natural compounds involved in many biological pathways. Since the discovery of their involvement in endocrine signal transduction, myo-Ins and D-chiro-Ins supplementation has contributed to clinical approaches in ameliorating many gynecological and endocrinological diseases. Currently both myo-Ins and D-chiro-Ins are well-tolerated, effective alternative candidates to the classical insulin sensitizers, and are useful treatments in preventing and treating metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS), gestational diabetes mellitus (GDM), and male fertility disturbances, like sperm abnormalities. Moreover, besides metabolic activity, myo-Ins and D-chiro-Ins deeply influence steroidogenesis, regulating the pools of androgens and estrogens, likely in opposite ways. Given the complexity of inositol-related mechanisms of action, many of their beneficial effects are still under scrutiny. Therefore, continuing research aims to discover new emerging roles and mechanisms that can allow clinicians to tailor inositol therapy and to use it in other medical areas, hitherto unexplored. The present paper outlines the established evidence on inositols and updates on recent research, namely concerning D-chiro-Ins involvement into steroidogenesis. In particular, D-chiro-Ins mediates insulin-induced testosterone biosynthesis from ovarian thecal cells and directly affects synthesis of estrogens by modulating the expression of the aromatase enzyme. Ovaries, as well as other organs and tissues, are characterized by a specific ratio of myo-Ins to D-chiro-Ins, which ensures their healthy state and proper functionality. Altered inositol ratios may account for pathological conditions, causing an imbalance in sex hormones. Such situations usually occur in association with medical conditions, such as PCOS, or as a consequence of some pharmacological treatments. Based on the physiological role of inositols and the pathological implications of altered myo-Ins to D-chiro-Ins ratios, inositol therapy may be designed with two different aims: (1) restoring the inositol physiological ratio; (2) altering the ratio in a controlled way to achieve specific effects

When one size does not fit all: Reconsidering PCOS etiology, diagnosis, clinical subgroups, and subgroup-specific treatments

Polycystic Ovary Syndrome (PCOS) is a complex endocrine disorder that affects a large proportion of women. Due to its heterogeneity, the best diagnostic strategy has been a matter of contention. Since 1990 scientific societies in the field of human reproduction have tried to define the pivotal criteria for the diagnosis of PCOS. The consensus Rotterdam diagnostic criteria included the presence of hyperandrogenism, oligo/anovulation, and polycystic ovarian morphology (PCOM), and have now been updated to evidence based diagnostic criteria in the 2018 and 2023 International Guideline diagnostic criteria endorsed by 39 societies internationally. Within the Rotterdam Criteria, at least two out of three of the above-mentioned features are required to be present to diagnose PCOS, resulting in four phenotypes being identified: phenotype A, characterized by the presence of all the features, phenotype B, exhibiting hyperandrogenism and oligo-anovulation, phenotype C, presenting as hyperandrogenism and PCOM and finally the phenotype D that is characterized by oligo-anovulation and PCOM, lacking the hyperandrogenic component. However, it is the hypothesis of the EGOI group that the Rotterdam phenotypes A, B, and C have a different underlying causality to phenotype D. Recent studies have highlighted the strong correlation between insulin resistance and hyperandrogenism, and the pivotal role of these factors in driving ovarian alterations, such as oligo-anovulation and follicular functional cyst formation. This new understanding of PCOS pathogenesis has led the authors to hypothesis that phenotypes A, B, and C are endocrine-metabolic syndromes with a metabolic clinical onset. Conversely, the absence of hyperandrogenism and metabolic disturbances in phenotype D suggests a different origin of this condition, and point towards novel pathophysiological mechanisms; however, these are still not fully understood. Further questions have been raised regarding the suitability of the “phenotypes” described by the Rotterdam Criteria by the publication by recent GWAS studies, which demonstrated that these phenotypes should be considered clinical subtypes as they are not reflected in the genetic picture. Hence, by capturing the heterogeneity of this complex disorder, current diagnostic criteria may benefit from a reassessment and the evaluation of additional parameters such as insulin resistance and endometrial thickness, with the purpose of not only improving their diagnostic accuracy but also of assigning an appropriate and personalized treatment. In this framework, the present overview aims to analyze the diagnostic criteria currently recognized by the scientific community and assess the suitability of their application in clinical practice in light of the newly emerging evidence

Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills

The Mössbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe3+-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe3+/FeT < 0.2) with Fe from olivine, pyroxene (Ol > Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, Keel, and Paros with Fe3+/FeT ~ 0.6–0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe2+ from Ol + Px is 40–49% and 9–24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm 3–6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt 10–15%). Remaining Fe is present as npOx, hematite, and goethite in variable proportions. Clovis has the highest goethite content (Fe from Gt = 40%). Goethite (α-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe3+/FeT ~ 0.3) occur throughout Gusev crater (60–80% Fe from Ol + Px, 10–30% from npOx, and 10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe3+-sulfate (65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust.Additional co-authors: E Kankeleit, P Gütlich, F Renz, SW Squyres, RE Arvidso